In a variety of fuel cells, a proton exchange membrane (PEM) is utilized most commonly. Hydrogen and oxygen are typically used in PEM fuel cells by chemical reaction between the catalyst layers to generate electricity and water without carbon dioxide during the reaction.
The key components in PEM fuel cells comprises the proton exchange membrane (PEM), bipolar plates, electrodes and hydrogen storage materials (fuel storage), etc., and the combinations thereof are referred to as a membrane electrode assembly (MEA), wherein the electrodes are made of two sheets of thin porous electrodes to be an anode and a cathode, and separated by a solid state polymer of the proton exchange membrane. One side of each sheet is coated with a catalyst, when hydrogen is introduced into the cell, the hydrogen is decomposed into electrons (E−) and protons (H+) by the anode catalyst. The electrons flow along the external circuit to supply power to a load (such as a motor or lamp), with the protons arriving the cathode through the proton exchange membrane. Then, the catalyst from the cathode side actuates the protons and the electrons reflowed from the load to combine with the oxygen in the air, so as to generate water and heat.
The main composition of the electrode catalyst layer is a composite layer formed of platinum and polymer electrolyte gel in micro phase separation, wherein the phases are staggered and permeate each other thereby transmit electrons, protons, and gases. The polymer electrolyte of the electrode catalyst layer must allow the protons and the reactive gases to enter into the reaction sites, and it also has the function of passing water. It is worth emphasizing that the polymer electrolyte in the electrode catalyst layer must have high conductivity for protons, unlike the polymer electrolyte in the proton exchange membrane which must have high permeability for reactive gases, the polymer electrolyte under a high acid and high temperature environment must have stable redox properties. Further, the polymer electrolyte of the catalyst layer and the proton exchange membrane must have compatibility and therefore be able to avoid delamination during long term operation or the production process of the components. That is to say, the polymer electrolyte of the catalyst layer and the proton exchange membrane preferably have a similar molecular structure.
Therefore, it is necessary to provide a fuel cell catalyst layer having sulfonated poly(acrylene ether)s and a manufacturing method thereof to solve the problems existing in conventional technologies, as described above.